In the field of photographic plate-making processes in which silver halide photographic light sensitive materials are used, there have been used the processes for making original printing blocks in such a manner that a photographic image having continuous gradation is converted into a so-called half-tone dotted image formed of the various sizes of half-tone dots and the resulting half-tone dotted image is used in combination with an already photographed letter or line original so that an original printing block can be prepared.
As for the silver halide photographic light sensitive materials applicable to the above-mentioned purpose, it has been required to use those having a high contrast and a high photographic density each capable of clearly discriminating between an imaged area and a non-imaged area, that is, those capable of showing ultra-high contrast photographic characteristics, so that a half-tone dotted image or the reproduction of letters or lines can be made excellent.
The methods for obtaining the above-mentioned characteristics include, for example, the methods in which a tetrazolium salt is used, such as those described in Japanese Patent Open to Public Inspection (hereinafter abbreviated to JP OPI Publication) Nos. 52-18317/1977, 53-95618/1978, 58-173737/1983 and 58-106943/1983; and the methods in which a hydrazine derivative is used, such as those described in U.S. Pat. Nos. 4,166,742, 4,168,977, 1,211,857, 4,224,401, 4,243,739, 4,272,606 and 4,311,781.
The developers used therein can be said to be suitable for developing light sensitive materials continuously while constantly replenishing them into an automatic processor, (the developing process is so-called a running process.), because these developers may not be more affected by an air oxidation, as compared to any conventional lith type developers.
In the above-mentioned running process, the improvements of light sensitive materials, processing solutions and replenishing methods have variously been made so that a stability can be realized by replenishing as small as possible. However, the techniques such as the above-mentioned still remain not satisfactory, but defective because of lowering a contrast and varying a sensitivity.
For stabilizing a running process carried out when making combination use of two or more kinds of plate-making materials, there are known techniques in which an inorganic halide, an alkylene oxide compound or a nitrogen-containing heterocyclic compound is contained in a backing layer or in an other layer of the light sensitive material, (refer to those described in JP OPI Publication No. 52-80024/1977 and so forth). However, these techniques are still not satisfactory in stabilizing the running process for a high-contrast light sensitive material containing a tetrazolium salt or a hydrazine derivative, particularly, in a small amount replenishing running-process. On the other hand, Example 1 given in JP OPI Publication No. 52-80024/1977 describes that polyethylene glycol is added to a backing layer. This particular case is quite different from this present invention in a running process, because in this case, at least two kinds of plate-making materials are used in combination, wherein a compound to be contained in a silver halide light sensitive material is contained in a backing layer of another light sensitive material.
In recent years, the drainage control regulations are getting severe particularly in urban communities, because of environmental protection problems.
Therefore, developing and fixing solutions wasted when processing light sensitive materials cannot be flowed into sewers, but generally collected by recyclers upon paying the collection expenses to them from individual users. The collection expenses are proportional to the amounts of the subject wasted solutions. When the amount of wasted solutions is smaller, it is more beneficial for the users and it can also easily be supposed to be preferable above all when taking the environmental problems into consideration.
Reduction of a wasted amount is to be that a replenishing amount is to further be reduced. Therefore, many problems may arise therefrom.
The first problem is that, when carrying out a running process, a sensitivity is further lowered than in ordinary running processes.
The second problems may sometimes arise when the concentration of the components dissolved out of a light sensitive material is increased in a developer and the compounds having a relatively low solubility among the dissolved-out compounds may be deposited in the developer.
The resulting deposited substances are present in the form of oil drops. They are deposited on the surfaces of the transport rollers of an automatic processor used and they are liable to adhere thereto as they are. Therefore, the deposits resultingly adhere to the surface of the processed light sensitive material.
The adhering matter is in the form of oil (that is so called oil sludge.) and it causes a partial development abnormality, because it hinders the permeation of a developer or fixer. If this is the case as it is, an image is seriously spoiled so that the resulting image cannot be worth using.
It has, therefore, been demanded to improve the above-described deterioration in light sensitive materials as soon as possible.